ACAPULCO, Mexico (Reuters) - Looting broke out in the flooded Mexican beach resort of Acapulco as the government struggled to reach tens of thousands of people cut off by flooding that had claimed at least 80 lives by Wednesday.

Stores were ransacked by looters who carried off everything from televisions to Christmas decorations after floodwaters wreaked havoc in the Pacific port that has experienced some of the worst storm damage to hit Mexico in years.

Tens of thousands of people have been trapped in the aftermath of two tropical storms that hammered vast swathes of Mexico. More than 1 million people have been affected. Acapulco's airport terminal was under water, stranding tourists.

Shops were plundered in the city's upscale neighborhood of Diamante, home to luxury hotels and plush apartments, where dozens of cars were ruined by muddy brown floodwaters. Marines were posted outside stores to prevent further theft.

"Unfortunately, it wasn't looting from need of food. It was stealing for stealing's sake," said Mariberta Medina, head of a local hoteliers' association. "They even stole Halloween and Christmas decorations and an outboard motor."

Northwest of Acapulco in the village of La Pintada, rescue workers have recovered the bodies of 18 people killed after a landslide buried their homes, the town's mayor said.

That death toll could rise because more than 60 people in the area have disappeared.

Torrential rains were spawned by two tropical storms, Ingrid and Manuel, which converged on Mexico from the Gulf and the Pacific over the weekend, triggering the flash floods.

Manuel strengthened to a tropical storm again on the Pacific coast on Wednesday, moving northwest toward the Baja California peninsula, the U.S. National Hurricane Center said.

Rescue workers in the state of Baja California Sur, home to the popular beach resorts of Los Cabos, prepared to evacuate people from flood-prone areas.

Manuel is forecast to become a hurricane later on Wednesday and will likely soak the states of Nayarit, Sinaloa and Baja California Sur in the next few days, the NHC said.

Another area of low pressure over Mexico's Yucatan Peninsula has a 70 percent chance of becoming a tropical cyclone in the next 48 hours. It is likely to dump more heavy rains across an area already hit by floods and mudslides.

On Wednesday afternoon, national emergency services said they had registered 80 deaths due to the storms.

As the cost of the flooding continued to mount, the Finance Ministry said it had around 12 billion pesos ($925.60 million)available in emergency funding.

EVACUATIONS

President Enrique Pena Nieto pledged to repair the damage quickly and was due to conduct a flyover of affected areas on the Gulf coast of Mexico on Wednesday.

The poor weather forced state oil monopoly Pemex to evacuate three oil platforms and halt drilling at some wells. A Pemex official said its refining operations had not been affected and that the company had seven days worth of inventory.

Pemex's refinery in Tamaulipas, its smallest, was partially flooded, but operations were still normal, the firm said. The Transport Ministry said all oil export terminals were open.

The rains pummeled several Mexican states, with Veracruz, Guerrero, Puebla, Hidalgo, Michoacan, Tamaulipas and Oaxaca among the hardest hit.

Landslides have buried homes and a bus in Veracruz on Mexico's eastern seaboard. Thousands were evacuated from flooded areas, some by helicopter, and taken to shelters.

Dozens of homes in Tampico, one of the main Gulf ports north of Veracruz, were waterlogged when the Panuco River burst its banks, forcing evacuations.

Crocodiles swam into the streets of Tampico.

"They don't bother the people," a spokesman for the state government of Tamaulipas said.

The port was operating as normal, he added.

Acapulco, whose reputation has suffered due to a surge in violence from warring drug gangs over the past three years, remains the biggest worry for the government.

The city is struggling to cope with the downpour that has submerged vast areas of the city, choked its palm-lined streets with mud and stranded about 40,000 visitors.

More than half of the deaths occurred in Guerrero, where Acapulco lies. Despite the loss of life, state Governor Angela Aguirre said the beach resort was "virtually back to normality."

About 5,300 stranded tourists in Acapulco have been taken to Mexico City, said Gerardo Ruiz Esparza, Mexico's minister for transport and communications.

But food and bottled water are scarce, and cash has been hard to come by after power outages knocked out bank machines.

"We waited for more than hour to get into a shop and only managed to get instant soup, some tins of tuna and two cartons of milk," said Clemencia Santana Garcia, 45, who sells goods on Acapulco's beaches. "This is going to get ugly."